Here's a patch that adds the missing read_is_locked() and
write_is_locked() macros for IA64. When combined with Ingo's patch, I
can boot an SMP kernel with CONFIG_PREEMPT on.
However, I feel these macros are misnamed: read_is_locked() returns true if
the lock is held for writing; write_is_locked() returns true if the
lock is held for reading or writing.
Signed-off-by: Peter Chubb <[EMAIL PROTECTED]>
Index: linux-2.6-bklock/include/asm-ia64/spinlock.h
===================================================================
--- linux-2.6-bklock.orig/include/asm-ia64/spinlock.h 2005-01-18
13:46:08.138077857 +1100
+++ linux-2.6-bklock/include/asm-ia64/spinlock.h 2005-01-19
08:58:59.303821753 +1100
@@ -126,8 +126,20 @@
#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 }
#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
+
#define rwlock_is_locked(x) (*(volatile int *) (x) != 0)
+/* read_is_locked -- - would read_trylock() fail?
+ * @lock: the rwlock in question.
+ */
+#define read_is_locked(x) (*(volatile int *) (x) < 0)
+
+/**
+ * write_is_locked - would write_trylock() fail?
+ * @lock: the rwlock in question.
+ */
+#define write_is_locked(x) (*(volatile int *) (x) != 0)
+
#define _raw_read_lock(rw)
\
do {
\
rwlock_t *__read_lock_ptr = (rw);
\
--
Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au
The technical we do immediately, the political takes *forever*
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